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The development of wearable bioelectronic systems is a promising approach for optimal delivery of therapeutic treatments. These systems can provide continuous delivery of ions, charged biomolecules, and an electric field for various medical applications. However, rapid prototyping of wearable bioelectronic systems for controlled delivery of specific treatments with a scalable fabrication process is challenging. We present a wearable bioelectronic system comprised of a polydimethylsiloxane (PDMS) device cast in customizable 3D printed molds and a printed circuit board (PCB), which employs commercially available engineering components and tools throughout design and fabrication. The system, featuring solution-filled reservoirs, embedded electrodes, and hydrogel-filled capillary tubing, is assembled modularly. The PDMS and PCB both contain matching through-holes designed to hold metallic contact posts coated with silver epoxy, allowing for mechanical and electrical integration. This assembly scheme allows us to interchange subsystem components, such as various PCB designs and reservoir solutions. We present three PCB designs: a wired version and two battery-powered versions with and without onboard memory. The wired design uses an external voltage controller for device actuation. The battery-powered PCB design uses a microcontroller unit to enable pre-programmed applied voltages and deep sleep mode to prolong battery run time. Finally, the battery-powered PCB with onboard memory is developed to record delivered currents, which enables us to verify treatment dose delivered. To demonstrate the functionality of the platform, the devices are used to deliver H[Formula: see text] in vivo using mouse models and fluoxetine ex vivo using a simulated wound environment. Immunohistochemistry staining shows an improvement of 35.86% in the M1/M2 ratio of H[Formula: see text]-treated wounds compared with control wounds, indicating the potential of the platform to improve wound healing.

Simple Summary: Neuroblastoma (NB), a prevalent childhood cancer, presents challenges in treatment due to its cellular diversity and the presence of tumor-derived endothelial cells (TECs) associated with chemoresistance. We lack specific biomarkers for TECs, hindering effective therapies. We developed a stiffness-based in vitro platform simulating arterial and venous conditions to address this gap. Notably, adrenergic NB cells transdifferentiated into TECs where there was an arterial-like stiffness, while mesenchymal cells did not. This platform facilitated the identification of Globotriaosylceramide (GB3) as a novel TEC biomarker. Moreover, we harnessed Shiga toxin-functionalized nanoparticles for the specific targeting of GB3-positive cells, showing promise for future therapeutic strategies. Our study provides insights into NB heterogeneity, offers a predictive tool for assessing aggressiveness, and introduces potential targets for precision therapies. Neuroblastoma (NB) is a childhood cancer in sympathetic nervous system cells. NB exhibits cellular heterogeneity, with adrenergic and mesenchymal states displaying distinct tumorigenic potentials. NB is highly vascularized, and blood vessels can form through various mechanisms, including endothelial transdifferentiation, leading to the development of tumor-derived endothelial cells (TECs) associated with chemoresistance. We lack specific biomarkers for TECs. Therefore, identifying new TEC biomarkers is vital for effective NB therapies. A stiffness-based platform simulating human arterial and venous stiffness was developed to study NB TECs in vitro. Adrenergic cells cultured on arterial-like stiffness transdifferentiated into TECs, while mesenchymal state cells did not. The TECs derived from adrenergic cells served as a model to explore new biomarkers, with a particular focus on GB3, a glycosphingolipid receptor implicated in angiogenesis, metastasis, and drug resistance. Notably, the TECs unequivocally expressed GB3, validating its novelty as a marker. To explore targeted therapeutic interventions, nanoparticles functionalized with the non-toxic subunit B of the Shiga toxin were generated, because they demonstrated a robust affinity for GB3-positive cells. Our results demonstrate the value of the stiffness-based platform as a predictive tool for assessing NB aggressiveness, the discovery of new biomarkers, and the evaluation of the effectiveness of targeted therapeutic strategies. [ABSTRACT FROM AUTHOR]

Objectives: In vivo, the principal function of mechanosensitive odontoblasts is to synthesize and secrete the matrix which then calcifies and forms reactive dentin after exposure to appropriate stimuli. This study aims to develop the influence of mechanical factors on dentinogenesis based on odontoblasts, which contribute to reparative dentin formation. Methods: We fabricated polydimethylsiloxane with different stiffnesses and seeded 17IIA11 odontoblast‐like cells on the substrates in different stiffnesses. Cell morphology was detected by scanning electron microscope, and the mineralization phenotype was detected by alkaline phosphatase staining and alizarin red staining, while expression levels of dentinogenesis‐related genes (including Runx2, Osx, and Alp) were assayed by qPCR. To explore mechanism, protein distribution and expression levels were detected by immunofluorescent staining, Western blotting, and immunoprecipitation. Results: In our results, during dentinogenesis, 17IIA11 odontoblast‐like cells appeared better extension on stiffer substrates. The binding between LAMB1 and FAK contributed to converting mechanical stimuli into biochemical signaling, thereby controlling mitogen‐activated protein kinase kinase 1/2 activity in stiffness‐driven dentinogenesis. Conclusion: The present study suggests odontoblast behaviors can be directly regulated by mechanical factors at cell–material interfaces, which offers fundamental mechanism in remodeling cell microenvironment, thereby contributing to physiological phenomena explanation and tissue engineering progress. [ABSTRACT FROM AUTHOR]

In this research, a series of silicone foam/polytitanosiloxane composites (SF-pTS) were fabricated with hydroxy-, vinyl-, hydrogen-containing polydimethylsiloxanes, and polytitanosiloxane filler in the presence of a platinum catalyst under ambient conditions. The effect of the amount of polytitasiloxane on the micromorphology and flame retardancy of silicone foam was studied, and a relative flame retardancy mechanism was proposed. It could be found that the polytitanosiloxane exhibited a good dispersion level in the silicone foam, thus improving the flame retardancy of the composite. When the content of polytitanosiloxane is 9 wt%, the limiting oxygen index and UL-94 grade of the SF-pTS9 composite are increased to 29.2% and FV-0, respectively. Cone experiment results suggested that the SF-pTS9 possessed relative balanced PHRR (148.9 kW/m2), THR (58.5 MJ/m2), TSP (0.6 m2), and mass residue (83.9%) among the prepared silicone foam materials. This work provides a new avenue to fabricate a silicone foam composite with enhanced flame retardancy. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxanes (PDMS) foam as one of next-generation polymer foam materials shows poor surface adhesion and limited functionality, which greatly restricts its potential applications. Fabrication of advanced PDMS foam materials with multiple functionalities remains a critical challenge. In this study, unprecedented self-adhesive PDMS foam materials are reported with worm-like rough structure and reactive groups for fabricating multifunctional PDMS foam nanocomposites decorated with MXene/cellulose nanofiber (MXene/CNF) interconnected network by a facile silicone foaming and dip-coating strategy followed by silane surface modification. Interestingly, such self-adhesive PDMS foam produces strong interfacial adhesion with the hybrid MXene/CNF nano-coatings. Consequently, the optimized PDMS foam nanocomposites have excellent surface super-hydrophobicity (water contact angle of ≈159o), tunable electrical conductivity (from 10-8 to 10 S m-1), stable compressive cyclic reliability in both wide-temperature range (from -20 to 200 °C) and complex environments (acid, sodium, and alkali conditions), outstanding flame resistance (LOI value of >27% and low smoke production rate), good thermal insulating performance and reliable strain sensing in various stress modes and complex environmental conditions. It provides a new route for the rational design and development of advanced PDMS foam nanocomposites with versatile multifunctionalities for various promising applications such as intelligent healthcare monitoring and fire-safe thermal insulation. [ABSTRACT FROM AUTHOR]

The main factors hindering the applicability of superhydrophobic coatings are their complex preparation methods, high cost, and poor mechanical stability. To address some of these issues, coatings using polydimethylsiloxanes (PDMS) with good mechanical stability having self-healing properties were prepared by combining the sodium chloride particles template with flame treatment technology. This coating demonstrated good superhydrophobicity due to the micro/nanostructure on its surface having a maximum water contact angle of 163° and a water sliding angle of less than 2°. Moreover, it exhibited good mechanical stability, which was examined by tape peeling and sandpaper abrasion tests. It was also observed that the damaged PDMS coating recovered its superhydrophobicity after flame treatment due to the partial decomposition of the polymers. We have shown that high-quality PDMS superhydrophobic coating can be prepared with a low-cost and simple method, which has great applicability potential in frost resistance and self-cleaning.This title is mismatch with jobsheet title. Please check if it is correct or not and proceed furtherThis title is correct. [ABSTRACT FROM AUTHOR]

Polydimethylsiloxane (PDMS) organogel sponges were prepared and studied in order to understand the role of pore size in an elastomeric network on the ability to uptake and release organic solvents. PDMS organogel sponges have been produced according to sugar leaching techniques by adding two sugar templates of different forms and grain sizes (a sugar cube template and a powdered sugar template), in order to obtain materials differing in porosity, pore size distribution, and solvent absorption and liquid retention capability. These materials were compared to PDMS organogel slabs that do not contain pores. The sponges were characterized by Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and compared with PDMS slabs that do not contain pores. Scanning electron microscopy (SEM) provided information about their morphology. X-ray micro-tomography (XMT) allowed us to ascertain how the form of the sugar templating agent influences the porosity of the systems: when templated with sugar cubes, the porosity was 77% and the mean size of the pores was ca. 300 μm; when templated with powdered sugar, the porosity decreased to ca. 10% and the mean pore size was reduced to ca. 75 μm. These materials, porous organic polymers (POPs), can absorb many solvents in different proportions as a function of their polarity. Absorption capacity, as measured by swelling with eight solvents covering a wide range of polarities, was investigated. Rheology data established that solvent absorption did not have an appreciable impact on the gel-like properties of the sponges, suggesting their potential for applications in cultural heritage conservation. Application tests were conducted on the surfaces of two different lab mock-ups that simulate real painted works of art. They demonstrated further that PDMS sponges are a potential innovative support for controlled and selective cleaning of works of art surfaces. [ABSTRACT FROM AUTHOR]

Introduction and hypothesisThis study aimed to report 3-year completed follow-up of the safety and efficacy of Macroplastique® (MPQ) in women with stress urinary incontinence (SUI) due to intrinsic sphincter deficiency (ISD).MethodsThis is a retrospective analysis of all women who completed 3-year follow-up post-MPQ injection(s) at ten medical centers. We used the ROSE registry data report of Macroplastique® [Macroplastique® Real-time Observation of Safety and Effectiveness (ROSE) registry P040050/PAS001 on 2017]. Subjective incontinence outcome and adverse effects were assessed.ResultsThe study included all patients (n = 70) who completed 3-year follow-up after the last MPQ injection. Twenty-four of 70 (34%) patients had two injections; 21/70 (30%) patients reported Stamey grade 0 and 28/70 (40%) reported Stamey grade 1. The overall patient satisfaction was 68% who completed 3-year follow-up. The composite success rate (I-QoL, PGI-S, and Stamey grade improvement) was 51.4%. No serious adverse events (AE) were reported within the completed 3-year follow-up.ConclusionsMPQ was found to be safe and efficacious for the treatment of SUI secondary to ISD in women. The overall high satisfaction rate was sustained from baseline to 3 years post-injection. Most complications were minor and transient without sequelae.

Rotaxanes consisting of a high‐molecular‐weight axle and wheel components (macro‐rotaxanes) have high structural freedom, and are attractive for soft‐material applications. However, their synthesis remains underexplored. Here, we investigated macro‐rotaxane formation by the topological trapping of multicyclic polydimethylsiloxanes (mc‐PDMSs) in silicone networks. mc‐PDMS with different numbers of cyclic units and ring sizes was synthesized by cyclopolymerization of a α,ω‐norbornenyl‐functionalized PDMS. Silicone networks were prepared in the presence of 10–60 wt % mc‐PDMS, and the trapping efficiency of mc‐PDMS was determined. In contrast to monocyclic PDMS, mc‐PDMSs with more cyclic units and larger ring sizes can be quantitatively trapped in the network as macro‐rotaxanes. The damping performance of a 60 wt % mc‐PDMS‐blended silicone network was evaluated, revealing a higher tan δ value than the bare PDMS network. Thus, macro‐rotaxanes are promising as non‐leaching additives for network polymers. [ABSTRACT FROM AUTHOR]

Supramolecular silicone elastomer is a promising material for sustainable development. Here, quadruple hydrogen bonded ureidopyrimidinone (UPy) units were grafted onto high molecular weight polydimethylsiloxanes (PDMS), providing a novel supramolecular silicone elastomer. The high molecular weight PDMS precursor was prepared through a cyclic trimeric phosphazene base catalyzed ring‐opening polymerization of Octamethylcyclotetrasiloxane (D4) and tetravinyltetramethylcyclotetrasiloxane (V4) with a well‐controlled vinyl content. Its side chains were modified by hydroxyl groups via a thiol‐ene reaction. Then UPy units were further grafted on the side chain of high molecular weight PDMS by the isocyanate‐hydroxy reaction. The mechanical and self‐healing properties of the elastomer can be controlled by adjusting the molecular weight of PDMS and the amount of UPy units. The obtained PDMS elastomers displayed excellent stretchability (elongation at break of 1513%), good self‐healing efficiency (76% at 60°C for 2 h), and high resilience (elastic recovery of 93% under 300% strain cyclic stretching). [ABSTRACT FROM AUTHOR]

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells of the same or different type, micropatterning techniques have proved useful. DNA Programmed Assembly of Cells (DPAC) is a micropatterning technique that targets the adhesion of cells to a substrate or other cells using DNA hybridization. The most basic operations in DPAC begin with decorating cell membranes with lipid-modified oligonucleotides, then flowing them over a substrate that has been patterned with complementary DNA sequences. Cells adhere selectively to the substrate only where they find a complementary DNA sequence. Non-adherent cells are washed away, revealing a pattern of adherent cells. Additional operations include further rounds of cell-substrate or cell-cell adhesion, as well as transferring the patterns formed by DPAC to an embedding hydrogel for long-term culture. Previously, methods for patterning oligonucleotides on surfaces and decorating cells with DNA sequences required specialized equipment and custom DNA synthesis, respectively. We report an updated version of the protocol, utilizing an inexpensive benchtop photolithography setup and commercially available cholesterol modified oligonucleotides (CMOs) deployed using a modular format. CMO-labeled cells adhere with high efficiency to DNA-patterned substrates. This approach can be used to pattern multiple cell types at once with high precision and to create arrays of microtissues embedded within an extracellular matrix. Advantages of this method include its high resolution, ability to embed cells into a three-dimensional microenvironment without disrupting the micropattern, and flexibility in patterning any cell type.

We report a covalent chemistry-based hepatocellular carcinoma (HCC)-specific extracellular vesicle (EV) purification system for early detection of HCC by performing digital scoring on the purified EVs. Earlier detection of HCC creates more opportunities for curative therapeutic interventions. EVs are present in circulation at relatively early stages of disease, providing potential opportunities for HCC early detection. We develop an HCC EV purification system (i.e., EV Click Chips) by synergistically integrating covalent chemistry-mediated EV capture/release, multimarker antibody cocktails, nanostructured substrates, and microfluidic chaotic mixers. We then explore the translational potential of EV Click Chips using 158 plasma samples of HCC patients and control cohorts. The purified HCC EVs are subjected to reverse-transcription droplet digital PCR for quantification of 10 HCC-specific mRNA markers and computation of digital scoring. The HCC EV-derived molecular signatures exhibit great potential for noninvasive early detection of HCC from at-risk cirrhotic patients with an area under receiver operator characteristic curve of 0.93 (95% CI, 0.86 to 1.00; sensitivity = 94.4%, specificity = 88.5%).

Neuromuscular circuits (NMCs) are vital for voluntary movement, and effective models of NMCs are needed to understand the pathogenesis of, as well as to identify effective treatments for, multiple diseases, including Duchenne's muscular dystrophy and amyotrophic lateral sclerosis. Microfluidics are ideal for recapitulating the central and peripheral compartments of NMCs, but myotubes often detach before functional NMCs are formed. In addition, microfluidic systems are often limited to a single experimental unit, which significantly limits their application in disease modeling and drug discovery. Here, we developed a microfluidic platform (MFP) containing over 100 experimental units, making it suitable for medium-throughput applications. To overcome detachment, we incorporated a reactive polymer surface allowing customization of the environment to culture different cell types. Using this approach, we identified conditions that enable long-term co-culture of human motor neurons and myotubes differentiated from human induced pluripotent stem cells inside our MFP. Optogenetics demonstrated the formation of functional NMCs. Furthermore, we developed a novel application of the rabies tracing assay to efficiently identify NMCs in our MFP. Therefore, our MFP enables large-scale generation and quantification of functional NMCs for disease modeling and pharmacological drug targeting.

Objectives/hypothesisUnilateral ML is a commonly performed surgery for dysphonia secondary to glottic insufficiency. The safety of this procedure performed in the outpatient setting has not been extensively examined. The purpose of the study was to assess the safety of outpatient unilateral ML in adults and determine the incidence and timing of postoperative complications across two tertiary-care academic medical centers.Study designRetrospective chart review, METHODS: A review of patients undergoing unilateral ML at two tertiary-care academic centers from 2011 to 2017 was performed. Patients undergoing bilateral medialization laryngoplasty, revision surgery, or those undergoing additional laryngeal framework procedures including arytenoid adduction were excluded. Patient demographics, operative details, and perioperative and postoperative complications were recorded. Comparisons were made between those individuals who underwent inpatient versus outpatient ML.ResultsOne hundred three total procedures met inclusion criteria. Fifty-seven were performed as outpatient procedures, and 46 individuals were observed for at least 23 hours following surgery. Silastic or Gore-Tex implants were used in all but two surgeries. There were no postoperative complications in either setting, including hematoma, dyspnea, wound infections or seromas.ConclusionsThe incidence of adverse events during and immediately following unilateral ML is very low. Patients can be discharged safely the day of surgery without geographic restrictions.Level of evidence4 Laryngoscope, 129:1647-1649, 2019.

The use of biochemical signaling to derive smooth muscle cells (SMCs) from mesenchymal stem cells (MSCs) has been explored, but the induction of a fully functional SMC phenotype remains to be a major challenge. Cell morphology has been shown to regulate MSC differentiation into various lineages, including SMCs. We engineered substrates with microgrooves to induce cell elongation to study the mechanism underlying the MSC shape modulation in SMC differentiation. In comparison to those on flat substrates, MSCs cultured on engineered substrates were elongated with increased aspect ratios for both cell body and nucleus, as well as augmented cytoskeletal tensions. Biochemical studies indicated that the microgroove-elongated cells expressed significantly higher levels of SMC markers. MicroRNA analyses showed that up-regulation of miR-145 and the consequent repression of KLF4 in these elongated cells promoted MSC-to-SMC differentiation. Rho/ROCK inhibitions, which impair cytoskeletal tension, attenuated cell and nuclear elongations and disrupted the miR-145/KLF4 regulation for SMC differentiation. Furthermore, cell traction force measurements showed that miR-145 is essential for the functional contractility in the microgroove-induced SMC differentiation. Collectively, our findings demonstrate that, through a Rho-ROCK/miR-145/KLF4 pathway, the elongated cell shape serves as a decisive geometric cue to direct MSC differentiation into functional SMCs.

A method for the preparation of polydimethylsiloxanes with grafted methoxy-substituted dibenzoylmethanatoboron difluoride has been described. The structures of prepared polymers were confirmed using NMR, IR spectroscopy and gel permeation chromatography methods. Their thermal properties were investigated using thermal gravimetric analysis, differential scanning calorimetry and thermomechanical analysis. The prepared polymers had good thermal (Td5% up to 393 °C) and thermo-oxidative (Td5% = 413 °C) stability. The polymers started to transit in a viscous flow state at about 40 °C (for 3 a) and at about 20 °C (for 3 b). The viscoelastic characteristics of prepared polymers were determined in the sinusoidal oscillating vibrations mode. It was shown that the studied polymers at low frequencies at room temperature are viscoelastic fluids (G′ < G″). Increasing the frequency led to inversion (crossover) of dependences G′ and G″, which indicated the transition of polymers from viscous to elastomeric behavior characteristics, and the beginning of the formation of a physical network. Optical properties were studied using electron absorption, steady-state and time-resolved fluorescence spectroscopy. It was shown that intramolecular H-dimers exist in the ground state. The polymers studied had a bright fluorescence in the solution and in the solid state, consisting of bands of monomer and excimer emission. Thermally-activated delayed fluorescence was observed in the solution and the solid state. The prepared polymers possess intriguing properties that make them useful as optical materials, sensors or imaging agents. [ABSTRACT FROM AUTHOR]

High performance microprobes for combined sensing of glucose and choline were fabricated using microcontact printing (μCP) to transfer choline oxidase (ChOx) and glucose oxidase (GOx) onto targeted sites on microelectrode arrays (MEAs). Most electroenzymatic sensing sites on MEAs for neuroscience applications are created by manual enzyme deposition, which becomes problematic when the array feature size is less than or equal to ∼100 μm. The μCP process used here relies on use of soft lithography to create features on a polydimethylsiloxane (PDMS) microstamp that correspond to the dimensions and array locations of targeted, microscale sites on a MEA. Precise alignment of the stamp with the MEA is also required to transfer enzyme only onto the specified microelectrode(s). The dual sensor fabrication process began with polyphenylenediamine (PPD) electrodeposition on all Pt microelectrodes to block common interferents (e.g., ascorbic acid and dopamine) found in brain extracellular fluid. Next, a chitosan film was electrodeposited to serve as an adhesive layer. The two enzymes, ChOx and GOx, were transferred onto different microelectrodes of 2 × 2 arrays using two different PDMS stamps and a microscope for stamp alignment. Using constant potential amperometry, the combined sensing microprobe was confirmed to have high sensitivity for choline and glucose (286 and 117 μA mM cm-2, respectively) accompanied by low detection limits (1 and 3 μM, respectively) and rapid response times (≤2 s). This work demonstrates the use of μCP for facile creation of multianalyte sensing microprobes by targeted deposition of enzymes onto preselected sites of a microelectrode array.

A simple, efficient procedure has been employed to effect intra- and inter-chain crosslinking of two commercially available thiolated poly(dimethylsiloxane) copolymers (T-PDMS) with 4–6% or 13–17% of mercaptopropyl side-chains. The thiol functional groups were converted to disulfides (D-PDMS) in chloroform solutions of I2. Importantly, the conditions employed avoid over-oxidation to other types of sulfur-containing species, and the concentration of T-PDMS during the crosslinking reaction dictated the rheological properties and liquid or solid nature of the D-PDMS. The procedure for obtaining the crosslinked copolymers is simpler than other approaches in the literature used to crosslink polysiloxane backbones and to modulate their properties. By changing the concentration of T-PDMS during the treatment with I2, the degree of intra- and inter-chain crosslinking can be controlled (as assessed qualitatively by the solid or liquid nature of the products and their viscoelastic properties). For each of the T-PDMS materials, there is a concentration threshold, above which products are solids, and below which they are oils. Liquid and solid materials were characterized using 1H and 13C solution-state and 13C solid-state NMR spectroscopy, respectively. They indicate greater than 90% conversion of thiols to disulfides in the presence of excess I2. The rheological behavior of the liquid products, solvent swelling ability of solid products, and the thermal stability of the reactants and products are described. Furthermore, the solid products exhibit some of the highest swelling values reported in the literature for poly(dimethylsiloxane) (PDMS) materials. As assessed by thermal gravimetric analyses, the disulfide-crosslinked materials are more stable thermally than the corresponding thiols. [ABSTRACT FROM AUTHOR]

Self‐healing polymer–carbon composites are seen as promising materials for future electronic devices, which must be able to restore not only their structural integrity but also electrical performance after cracking and wear. Despite multiple reports about self‐healing conductive elements, there is a lack of a broad fundamental understanding of correlation between viscoelasticity of such composites, their electrical properties, and self‐healing of their mechanical as well as electrical properties. Here, it is reported thorough investigation of electromechanical properties of blends of carbon black (CB) as conductive filler and viscoelastic polymers (polydimethylsiloxanes (PDMS) and polyborosiloxane (PBS)) with different relaxation times as matrices. It is shown that behavior of composites depends strongly on the viscoelastic properties of polymers. Low molecular polymer composite possesses high conductivity due to strong filler network formation, quick electrical, and mechanical properties restoration, but for this the ability is sacrificed to flow and ductility at large deformation (material is brittle). In contrary, high relaxation time polymer composite behaves elastically on small time and flows at large time scale due to weak filler network and can heal. However, the electrical properties are worse than that of carbon and viscous polymer and degrade with time. [ABSTRACT FROM AUTHOR]

Extracorporeal membrane oxygenation (ECMO) is a life support system that circulates the blood through an oxygenating system to temporarily (days to months) support heart or lung function during cardiopulmonary failure until organ recovery or replacement. Currently, the need for high levels of systemic anticoagulation and the risk for bleeding are main drawbacks of ECMO that can be addressed with a redesigned ECMO system. Our lab has developed an approach using microelectromechanical systems (MEMS) fabrication techniques to create novel gas exchange membranes consisting of a rigid silicon micropore membrane (SμM) support structure bonded to a thin film of gas-permeable polydimethylsiloxane (PDMS). This study details the fabrication process to create silicon membranes with highly uniform micropores that have a high level of pattern fidelity. The oxygen transport across these membranes was tested in a simple water-based bench-top set-up as well in a porcine in vivo model. It was determined that the mass transfer coefficient for the system using SµM-PDMS membranes was 3.03 ± 0.42 mL O2 min-1 m-2 cm Hg-1 with pure water and 1.71 ± 1.03 mL O2 min-1 m-2 cm Hg-1 with blood. An analytic model to predict gas transport was developed using data from the bench-top experiments and validated with in vivo testing. This was a proof of concept study showing adequate oxygen transport across a parallel plate SµM-PDMS membrane when used as a membrane oxygenator. This work establishes the tools and the equipoise to develop future generations of silicon micropore membrane oxygenators.

When a constraint is removed, confluent cells migrate directionally into the available space. How the migration directionality and speed increase are initiated at the leading edge and propagate into neighboring cells are not well understood. Using a quantitative visualization technique-Particle Image Velocimetry (PIV)-we revealed that migration directionality and speed had strikingly different dynamics. Migration directionality increases as a wave propagating from the leading edge into the cell sheet, while the increase in cell migration speed is maintained only at the leading edge. The overall directionality steadily increases with time as cells migrate into the cell-free space, but migration speed remains largely the same. A particle-based compass (PBC) model suggests cellular interplay (which depends on cell-cell distance) and migration speed are sufficient to capture the dynamics of migration directionality revealed experimentally. Extracellular Ca2+ regulated both migration speed and directionality, but in a significantly different way, suggested by the correlation between directionality and speed only in some dynamic ranges. Our experimental and modeling results reveal distinct directionality and speed dynamics in collective migration, and these factors can be regulated by extracellular Ca2+ through cellular interplay. Quantitative visualization using PIV and our PBC model thus provide a powerful approach to dissect the mechanisms of collective cell migration.

In this work, we introduce, to our knowledge, a new set of adhesion-based biomarkers for characterizing mammalian cells. Mammalian cell adhesion to the extracellular matrix influences numerous physiological processes. Current in vitro methods to probe adhesion focus on adhesive force to a single surface, which can investigate only a subcomponent of the adhesive, motility, and polarization cues responsible for adhesion in the 3D tissue environment. Here, we demonstrate a method to quantify the transhesive properties of cells that relies on the microscale juxtaposition of two extracellular matrix-coated surfaces. By multiplexing this approach, we investigate the unique transhesive profiles for breast cancer cells that are adapted to colonize different metastatic sites. We find that malignant breast cancer cells readily transfer to new collagen I surfaces, and away from basement membrane proteins. Integrins and actin polymerization largely regulate this transfer. This tool can be readily adopted in cell biology and cancer research to uncover, to our knowledge, novel drivers of adhesion (or de-adhesion) and sort cell populations based on complex phenotypes with physiological relevance.

Wound repair is a key feature distinguishing living from nonliving matter. Single cells are increasingly recognized to be capable of healing wounds. The lack of reproducible, high-throughput wounding methods has hindered single-cell wound repair studies. This work describes a microfluidic guillotine for bisecting single Stentor coeruleus cells in a continuous-flow manner. Stentor is used as a model due to its robust repair capacity and the ability to perform gene knockdown in a high-throughput manner. Local cutting dynamics reveals two regimes under which cells are bisected, one at low viscous stress where cells are cut with small membrane ruptures and high viability and one at high viscous stress where cells are cut with extended membrane ruptures and decreased viability. A cutting throughput up to 64 cells per minute-more than 200 times faster than current methods-is achieved. The method allows the generation of more than 100 cells in a synchronized stage of their repair process. This capacity, combined with high-throughput gene knockdown in Stentor, enables time-course mechanistic studies impossible with current wounding methods.

[Display omitted] • An extremely simple emulsion gel (EG) system is constructed by glutamic acid (Glu) and carefully engineered polysiloxanes (AESi). • The formation of EG did not need the addition of extra surfactants. • The stability of EG was provided by the in situ formed AESi/Glu supramolecular complex. Emulsion gels (EGs), combined the advantages of both emulsions and gels, have attracted much attention in colloid chemistry. However, the preparation of EGs is usually complicated, which greatly hinders their development. Herein, we prepared a polydimethylsiloxane (PDMS) derivative which bears poly (ethoxylated ether) (PEO) segments at the ends and a few alkylamine groups on the side (denoted as AESi hereafter). When being mixed with an acidic amino acid (glutamic acid, Glu) in water, the amine groups of AESi were protonated, leading to an abrupt increase of its solubility. The AESi/Glu complex acts as a supramolecular amphiphile, which can form capsules in water. It can also stabilize excess AESi to form self-confined emulsions. In high loading of AESi, the emulsion droplets stack closely to form highly stable EGs. The EGs possess good viscoelasticity and are tunable by changing temperature or adding inorganic salts. By performing control experiments, structural features of the PDMS derivative and organic acid needed for the construction of EGs have been clarified. The strategy presented in this study provides new opportunity for the preparation and applications of EGs. [ABSTRACT FROM AUTHOR]

Leafy green surface microbiology studies often experience significant variations in results due to the heterogeneous nature of leaf surfaces. To provide a precise and controllable substitute, we microfabricated double-sided artificial leafy green phylloplanes using polydimethylsiloxane (PDMS) with a vinyl-terminated polyethylene glycol chain-based hydrophobicity modifier (PDMS-PEG) to modify PDMS hydrophobicity. We further tested the properties and applications of these artificial leaves, by examining the function of epicuticular wax, growth and survival of E. coli O157:H7 87-23 on the surface, and removal of attached E. coli cells via sanitation. The double-sided PDMS-PDMS-PEG leaves well-replicated their natural counterparts in macroscopic and microscopic structure, hydrophobicity, and E. coli O157:H7 87-23 attachment. After depositing natural epicuticular wax onto artificial leaves, the leaf surface wetting ability decreased, while E. coli O157:H7 87-23 surface retention increased. The artificial leaves supplied with lettuce lysate or bacterial growth media supported E. coli O157:H7 87-23 growth and survival similarly to those on natural leaves. In the sanitation test, the artificial lettuce leaves also displayed patterns similar to those of natural leaves regarding sanitizer efficiency. Overall, this study showcased the microfabrication and applications of double-sided PDMS-PDMS-PEG leaves as a replicable and controllable platform for future leafy green food safety studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Introduction: Unilateral vocal fold paralysis or paresis (UVFP) is a condition that causes significant morbidity due to dysphonia, dysphagia, and aspiration. Type I medialization thyroplasty (MT) is the current mainstay surgical treatment for UVFP. Though widely considered a safe procedure, concerns exist over possible airway complications which can lead to overnight observation. Herein, we report a systematic review of the safety and adverse events of MT to aid in determining the safety of same-day discharge., Data Sources: PubMed and Embase databases., Review Methods: Our search identified studies investigating complications associated with MT. Articles were selected if published between January 1, 1989 and March 15, 2023. Abstracts were screened, and data were extracted from included studies. Only Type I MT procedures were included; case reports were excluded. Participant characteristics, intervention details, results, and adverse events were extracted., Results: The database query identified 751 abstracts, of which 46 studies met eligibility criteria. A total of 2426 patients underwent MT. The most common implant was Silastic (n = 898, 37.0%) followed by Gore-Tex (n = 664, 27.4%). There were 254 (10.5%) total complications reported; 110 (4.5%) were considered major. The most common complication was nonobstructive hematoma (n = 59, 2.4%) followed by hemorrhage (n = 36, 1.5%). Implant extrusion (n = 24, 0.99%) or displacement (n = 15, 0.62%) occurred mostly in Silastic and Gore-Tex implants. Same-day discharge occurred with 429 patients and was not associated with adverse events., Conclusions: UVFP can be reliably improved by MT with a low risk of complications. Outpatient MT is a promising treatment with a favorable safety profile. Laryngoscope, 134:1994-2004, 2024., (© 2023 The American Laryngological, Rhinological and Otological Society, Inc.)

We treated six patients with the combination of anterograde distal interphalangeal joint arthrodesis and Swanson prothesis proximal interphalangeal joint arthroplasty on the same finger. The results showed both bony union and flexibility, without cases of nail deformity, wound complications, tip hypersensitivity or malalignment., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and publication of this article.

In the context of wound healing and tissue regeneration, precise control of cell migration direction is deemed crucial. To address this challenge, polydimethylsiloxane (PDMS) platforms with patterned 10 nm thick TiO x in arrowhead shape were designed and fabricated. Remarkably, without tall sidewall constraints, MC3T3-E1 cells seeded on these platforms were constrained to migrate along the tips of the arrowheads, as the cells were guided by the asymmetrical arrowhead tips which provided large contact areas. To the best of our knowledge, this is the first study demonstrating the use of thin TiO x arrowhead pattern in combination with a cell-repellent PDMS surface to provide guided cell migration unidirectionally without tall sidewall constraints. Additionally, high-resolution fluorescence imaging revealed that the asymmetrical distribution of focal adhesions, triggered by the patterned TiO x arrowheads with arm lengths of 10, 20, and 35 μm, promoted cell adhesion and protrusion along the arrowhead tip direction, resulting in unidirectional cell migration. These findings have important implications for the design of biointerfaces with ultrathin patterns to precisely control cell migration. Furthermore, microelectrodes were integrated with the patterned TiO x arrowheads to enable dynamic monitoring of cell migration using impedance measurement. This microfluidic device integrated with thin layer of guiding pattern and microelectrodes allows simultaneous control of directional cell migration and characterization of the cell movement of individual MC3T3-E1 cells, offering great potential for the development of biosensors for single-cell monitoring., (© 2024. The Author(s).)

The culture-based methods for viable Escherichia coli (E. coli) detection suffer from long detection time and laborious procedures, whereas the molecule tests and immune recognition technologies lack live/dead E. coli differentiation. Rapid, easy-to-use, and accessible viable E. coli detection is of benefit to bacterial infection diagnosis and risk warning of E. coli contamination of water and food, safeguarding human health. Herein, we propose a microwell chip-based solution to realize simple and rapid determination of viable E. coli. The vertical channel-well configuration is applied to develop the microwell array chip for increasing the microwell density (6200 wells/cm 2 ), yielding a broad dynamic range from 10 3 to 10 7 CFU/mL. We incorporate an inducible enzyme assay with the developed chip and achieve the differentiation of live/dead E. coli within 4 h, significantly shortening the detection time from over 24 h in the standard method. By encapsulating single E. coli into microwells, the concentration of viable cells can be determined simultaneously through counting positive microwells. In addition, the air soluble PDMS that can store negative pressure for independent sample digitalization endows the developed chip with simple operation and less reliance on external equipment. With further developments for increasing the number of microwell and integrating more sample panels, the developed chip can become a useful tool for rapid viable E. coli enumeration with user-friendly operation, simple procedures, and accessibility in decentralized settings, thereby deploying this device for water and food safety monitoring, as well as clinical bacterial infection diagnosis., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

A novel organic-inorganic gliclazide-loaded composite bead was developed by an ionic gelation process using acidified CaCl 2 , chitosan and tetraethylorthosilicate (TEOS) as a crosslinker. The beads were manufactured by crosslinking an inorganic silicone elastomer (-OH terminated polydimethylsiloxane, PDMS) with TEOS at different ratios before grafting onto an organic backbone (Na-alginate) using a 3 2 factorial experimental design. Gliclazide's encapsulation efficiency (EE%) and drug release over 8 h (% DR 8 h) were set as dependent responses for the optimisation of a pharmaceutical formula (herein referred to as 'G op') by response surface methodology. EE % and %DR 8 h of G op were 93.48% ± 0.19 and 70.29% ± 0.18, respectively. G op exhibited a controlled release of gliclazide that follows the Korsmeyer-Peppas kinetic model (R 2 = 0.95) with super case II transport and pH-dependent swelling behaviour. In vitro testing of G op showed 92.17% ± 1.18 cell viability upon testing on C2C12 myoblasts, indicating the compatibility of this novel biomaterial platform with skeletal muscle drug delivery.

The growing interest in microfluidic biosensors has led to improvements in the analytical performance of various sensing mechanisms. Although various sensors can be integrated with microfluidics, electrochemical ones have been most commonly employed due to their ease of miniaturization, integration ability, and low cost, making them an established point-of-care diagnostic method. This concept can be easily adapted to the detection of biomarkers specific to certain cancer types. Pathological profiling of hepatocellular carcinoma (HCC) is heterogeneous and rather complex, and biopsy samples contain limited information regarding the tumor and do not reflect its heterogeneity. Circulating tumor DNAs (ctDNAs), which can contain information regarding cancer characteristics, have been studied tremendously since liquid biopsy emerged as a new diagnostic method. Recent improvements in the accuracy and sensitivity of ctDNA determination also paved the way for genotyping of somatic genomic alterations. In this study, three-electrode (Au-Pt-Ag) glass chips were fabricated and combined with polydimethylsiloxane (PDMS) microchannels to establish an electrochemical microfluidic sensor for detecting c.747G > T hotspot mutations in the TP53 gene of ctDNAs from HCC. The preparation and analysis times of the constructed sensor were as short as 2 h in total, and a relatively high flow rate of 30 µl/min was used during immobilization and hybridization steps. To the best of our knowledge, this is the first time a PDMS-based microfluidic electrochemical sensor has been developed to target HCC ctDNAs. The system exhibited a limit of detection (LOD) of 24.1 fM within the tested range of 2-200 fM. The sensor demonstrated high specificity in tests conducted with fully noncomplementary and one-base mismatched target sequences. The developed platform is promising for detecting HCC-specific ctDNA at very low concentrations without requiring pre-enrichment steps., (© 2024. The Author(s).)

Cyclic and linear siloxanes are compounds synthesized from silicon consisting of alternating atoms of silicone and oxygen [Si-O] units with organic side chains. The most common cyclic siloxanes are octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), while the most common linear siloxanes are high molecular weight polydimethylsiloxanes (PDMS) and low molecular weight volatile linear siloxanes known as hexamethyldisiloxane (L2), octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5). These compounds (1) exhibit low dermal toxicity, (2) are generally inert and non-reactive, and (3) are compatible with a wide range of chemicals offering beneficial chemical properties which include the following: wash-off or transfer resistance from the skin, sun protection factor (SPF) enhancement, emolliency in cleaning products). Because of these properties, these compounds are incorporated into multiple consumer products for use on the skin, such as cosmetics and health-care products, with over 300,000 tons annually sold into the personal care and consumer products sector. Because of their widespread use in consumer products and potential for human dermal exposure, a comprehensive understanding of the dermal absorption and overall fate of siloxanes following dermal exposure is important. This review summarizes available data associated with the dermal absorption/penetration as well as fate of the most commonly used siloxane substances.

The complexity of the subsurface contaminated by chlorinated solvents such as trichloroethylene (TCE) makes it challenging to gain a complete understanding of contamination distribution and establish a conceptual site model (CSM). High-resolution vertical contaminant concentration profiling across both the unsaturated zone and the saturated aquifer is desirable for mapping the distribution of contamination. A Fick's law-based polydimethylsiloxane (PDMS) dialysis passive sampler was developed and evaluated on a field scale for its potential application. This study tests the passive sampler at two TCE contaminated sites, and the sampling results were compared with the results from different sampling methods based on the relative percent difference. The PDMS dialysis passive sampler obtained more representative soil gas concentrations in the unsaturated zone than a portable monitoring and sampling device, which caused soil gas flow disturbance by soil gas pumping during sample collection. In the saturated aquifer sampling, the results obtained by the PDMS dialysis passive sampler correlated well with those obtained by a commercial polyethylene passive diffusion bag, and exhibited higher sensitivity under low TCE concentration conditions. Furthermore, the PDMS dialysis passive samplers were densely deployed inside each monitoring well at multiple depths, at two sites, to achieve high-resolution monitoring across the unsaturated zone and saturated aquifer. Based on the PDMS dialysis sampler data, a more comprehensive three-dimensional CSM was systematically established., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Chenju Liang reports financial support was provided by Taiwan Environmental Protection Administration., (Copyright © 2024. Published by Elsevier Ltd.)

Multifunctional textiles have attracted widespread attention with the improvement of awareness of health. Especially, the fluorine-free superhydrophobic and conductive cellulose fiber-based fabrics have received intensive interest due to their broad and high-value applications. Herein, the copper sulfide nanoflowers were in-situ deposited on cotton fabric followed by polydimethylsiloxane (PDMS) treatment for encapsulating CuS nanoflowers and obtaining superhydrophobicity, recorded as Cot@PTA@CuS@PDMS. Cot@PTA@CuS@PDMS possesses superhydrophobicity with contact angles of 153.0 ± 0.4°, photothermal effect, excellent UV resistance, good conductivity, and anti-fouling. Interestingly, the resistance of Cot@PTA@CuS@PDMS is significantly reduced from 856.4 to 393.1 Ω under simulated sunlight irradiation with 250 mW/cm 2 . Notably, the resistance can be slightly recovered after shutting off simulated sunlight. Besides, Cot@PTA@CuS@PDMS has efficient oil-water separation efficiency for corn germ oil and castor oil, respectively. Briefly, this work provides a novel, facile, and promising strategy to fabricate multifunctional fiber-based textiles with the reversible change of resistance under simulated sunlight irradiation, inspiring more scholars to control the resistance change of textiles by light irradiation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tungiasis (sand flea disease) is a neglected tropical disease that is endemic in Sub-Saharan Africa and Latin America. Tungiasis causes pain, mobility restrictions, stigmatisation and reduced quality of life. Very severe cases with hundreds of sand fleas have been described, but treatment of such cases has never been studied systematically. During a larger community-based tungiasis control programme in a hyperendemic region in Karamoja, northeastern Uganda, 96 very severe tungiasis cases were identified and treated with the dimeticone formula NYDA®. They were repeatedly followed-up and treated again when necessary. The present study traces tungiasis frequency, intensity and morbidity among these 96 individuals over 2 years. At baseline, very severe tungiasis occurred in all age groups, including young children. Throughout the intervention, tungiasis frequency decreased from 100% to 25.8% among the 96 individuals. The overall number of embedded sand fleas in this group dropped from 15,648 to 158, and the median number of embedded sand fleas among the tungiasis cases decreased from 141 to four. Walking difficulties were reported in 96.9% at the beginning and in 4.5% at the end of the intervention. Repeated treatment with the dimeticone formula over 2 years was a successful strategy to manage very severe cases in a hyperendemic community. Treatment of very severe cases is essential to control the spread and burden of tungiasis in endemic communities., (© 2024 The Authors Tropical Medicine & International Health Published by John Wiley & Sons Ltd.)

Recent advancements in bioengineering have introduced potential alternatives to liver transplantation via the development of self-assembled liver organoids, derived from human-induced pluripotent stem cells (hiPSCs). However, the limited maturity of the tissue makes it challenging to implement this technology on a large scale in clinical settings. In this study, we developed a highly efficient method for generating functional liver organoids from hiPSC-derived carboxypeptidase M liver progenitor cells (CPM+ LPCs), using a microwell structure, and enhanced maturation through direct oxygenation in oxygen-permeable culture plates. We compared the morphology, gene expression profile, and function of the liver organoid with those of cells cultured under conventional conditions using either monolayer or spheroid culture systems. Our results revealed that liver organoids generated using polydimethylsiloxane-based honeycomb microwells significantly exhibited enhanced albumin secretion, hepatic marker expression, and cytochrome P450-mediated metabolism. Additionally, the oxygenated organoids consisted of both hepatocytes and cholangiocytes, which showed increased expression of bile transporter-related genes as well as enhanced bile transport function. Oxygen-permeable polydimethylsiloxane membranes may offer an efficient approach to generating highly mature liver organoids consisting of diverse cell populations., (© 2024 The Authors. Biotechnology and Bioengineering published by Wiley Periodicals LLC.)

Applying mechanical forces to tissues helps to understand morphogenesis and homeostasis. Additionally, recording the dynamics of living tissues under mechanical constraints is needed to explore tissue biomechanics. Here, we present a protocol to 3D-print a StretchCo device and use it to apply uniaxial mechanical stress on the Drosophila pupal dorsal thorax epithelium. We describe steps for 3D printing, polydimethylsiloxane (PDMS) strip cutting, and glue preparation. We detail procedures for PDMS strip mounting, tissue compaction, and live imaging upon force application. For additional details on the use and execution of this protocol, please refer to Cachoux et al. (2023) 1 from which the StretchCo machine has been derived., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024. Published by Elsevier Inc.)

Synthetic materials used for valid and reliable implant testing and design should reflect the mechanical and morphometric properties of human bone. Such bone models are already available on the market, but they do not reflect the population variability of human bone, nor are they open-celled porous as human bone is. Biomechanical studies aimed at cementing the fracture or an implant cannot be conducted with them. The aim of this study was to investigate the influence of a cell stabilizer on polyurethane-based cancellous synthetic bone in terms of morphology, compressive mechanics, and opening of the cancellous bone structure for bone cement application. Mechanical properties of cylindrical specimens of the bone surrogates were determined by static compression tests to failure. Furthermore, a morphometric analysis was performed using microcomputed tomography. To prove the open-cell nature of the bone surrogates, an attempt was made to apply bone cement. Effects on the mechanical properties of the polyurethane-based bone surrogates were observed by the addition of polydimethylsiloxane. All mechanical parameters like Young's modulus, ultimate stress and yield stress increased statistically significantly with increasing amounts of cell stabilizer (all p > 0.001), except for yield stress. The analysis of morphometric parameters showed a decrease in trabecular thickness, spacing and connectivity density, which was accompanied by an increase in trabecular number and an increase in pore size. The open-cell nature was proven by the application and distribution of bone cement in specimens with stabilizer, which was visualized by X-ray. In conclusion, the results show that by adding a cell stabilizer, polyurethane-based cancellous bone substrates can be produced that have an open-cell structure similar to human bone. This makes these bone surrogates suitable for biomechanical testing of osteosyntheses and for osteosynthesis cementation issues., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Marianne Hollensteiner reports financial support was provided by Austrian Science Fund. Marianne Hollensteiner reports financial support was provided by Paracelsus Medical Private University. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Wound infection and adhesion are important factors affecting wound healing. Early detection of pathogen infection and reduction of wound-to-dressing adhesion are critical for improving wound healing. Herein, Ester-J, which can rapidly respond to lipase secreted by bacteria, was designed and synthesized. Then, Ester-J was co-spun with poly(lactic-co-glycolic acid) (PLGA) and polydimethylsiloxane (PDMS) to prepare a PP-EsJ hydrophobic anti-adhesion dressing with a contact angle of 140.7°. When the PP-EsJ membrane came into contact with the bacteria, the loaded Ester-J was hydrolyzed to Tph-TSF-OH, releasing bright cyan-blue fluorescence, thus providing a fluorescence switch for an early warning of infection. The detection limits of PP-EsJ for Pseudomonas aeruginosa and Staphylococcus aureus were 1.0 × 10 5 and 1.0 × 10 6  CFU/mL, respectively. Subsequently, Tph-TSF-OH released 1 O 2 through light irradiation, which rapidly killed P. aeruginosa and S. aureus, and accelerated wound healing. Compared with the control group, enhanced wound closure (up to 99.80 ± 1.10 %) was observed in mice treated with the PP-EsJ membrane. The PP-EsJ membrane not only effectively reduced the risk of external infection but also reduced adhesions to the skin during dressing changes. These characteristics make PP-EsJ membranes potentially useful for clinical treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: To evaluate the long-term outcomes of polydimethylsiloxane (Macroplastique (MPQ)) in women with stress urinary incontinence (SUI) secondary to intrinsic sphincter deficiency (ISD) using validated questionnaires., Methods: Following IRB approval, charts of non-neurogenic women with SUI secondary to ISD who underwent MPQ injection were reviewed from a prospectively maintained database. ISD was defined as positive stress test with a well-supported urethra and low Valsalva leak point pressure when available. Excluded were women with follow-up <5years. Baseline data included validated questionnaire scores (UDI-6 question 3 (0-3), VAS Quality of Life, Incontinence Impact Questionnaire (IIQ-7)) and urodynamic study findings. Patients were followed with same questionnaires and three-dimensional ultrasound evaluating volume/configuration of MPQ. All three-dimensional ultrasound measurements were performed by the same imaging team blinded to clinical outcomes. Outcomes were evaluated in four groups based on prior SUI treatment. Success was defined as UDI-6 question 3 score of 0-1 and not requiring additional anti-incontinence therapy at the last visit after the last MPQ injection., Results: From April 2011-December 2016, 106 patients (median age 67) met study criteria. Median follow-up time was 7.4years. Median MPQ injected was 5 mL. Overall success was 43%, with 54% successful after one injection and 46% requiring ≥2 injections. Across all groups, patients had improvement in Quality of Life and IIQ-7 Question 7 (frustration). Among the failure group, 17% opted for a secondary autologous sling procedure., Conclusion: MPQ demonstrated long-term favorable outcomes in a subset of women with SUI secondary to ISD., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Polydimethylsiloxane (PDMS) is the most widely used material for passive dosing. However, the ability of PDMS to maintain constant water concentrations of chemicals in large-volume bioassays was insufficiently investigated. In this study, we proposed a kinetic-based method to determine the buffering capacity of PDMS for maintaining constant water concentrations of hydrophobic organic contaminants (HOCs) in large-volume bioassays. A good correlation between log K ow and PDMS-water partitioning coefficients (log K PW ) was observed for HOCs with log K ow values ranging from 3.30 to 7.42. For low-molecular-weight HOCs, volatile loss was identified as the primary cause of unstable water concentrations in passive dosing systems. Slow desorption from PDMS resulted in a reduction of water concentrations for high-molecular-weight HOCs. The volume ratio of PDMS to water (R V ) was the key factor controlling buffering capacity. As such, buffering capacity was defined as the minimum R V required to maintain 90% of the initial water concentration and was determined to be 0.0076-0.032 for six representative HOCs. Finally, passive dosing with an R V of 0.014 was validated to effectively maintain water concentrations of phenanthrene in 2-L and 96-h toxicity tests with adult mosquitofish. By determining buffering capacity of PDMS, this study recommended specific R V values for cost-efficient implementation of passive dosing approaches in aquatic toxicology, particularly in large-volume bioassays., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Over the years, the increasing prevalence of head lice infestation has led to an increase in treatment-related costs and the development of resistance to pediculicides. This study aimed to evaluate pediculicide sales over an 8-year period (2015-2022), including the COVID-19 pandemic., Methods: Data on products registered in the Turkish Pharmaceutical Index Dataview, Intercontinental Medical Statistics (IMS) database, sold on prescription and approved by the Ministry of Health in Türkiye were formally requested from the research organization IQVIA for pharmacologically active pediculicides (PAP) such as permethrin, pyrethrin, and sumithrin. Data for physically active products containing dimethicone (DMT) were obtained from the relevant pharmaceutical companies. Sale revenues were determined based on sale prices in the aforementioned year., Results: Total sales of pediculicides decreased from 2,452,846 units in 2015 to 2,028,840 units in 2022. While PAP consumption decreased over the years, from 1,832,006 to 518,460 units, DMT consumption increased from 620,840 to 1,510,380 units, from 2015 to 2022. The total price of pediculicides for the consumer increased more than threefold in Turkish currency. In terms of USD, an almost similar amount of money was spent over the years, with the exception of 2022 when the expenditure almost halved mainly due to the high inflation rate in the country., Conclusion: The decrease in PAP and the increase in DMT indicate that local lice have developed resistance to the former. Further studies are needed to determine the possible development of resistance in the country., (© 2024 The Authors. International Journal of Dermatology published by Wiley Periodicals LLC on behalf of the International Society of Dermatology.)

Statement of Problem: Computer-aided design and computer-aided manufacturing (CAD-CAM) technologies have become popular for manufacturing complete dentures. However, the adhesive strength of resilient liners to the polymers used to fabricate CAD-CAM complete dentures is unclear., Purpose: The purpose of this in vitro study was to determine the adhesive strength of 3 long-term resilient liners to CAD-CAM denture base polymers and heat-polymerized PMMA with thermocycling., Material and Methods: A total of 90 specimens were fabricated, 30 per group of denture base material (Lucitone 199, Ivo Base CAD, Denture Base LP). For each denture base polymer, 10 specimens were relined with 1 of 3 resilient liners (Permasoft, Mucopren Soft, Molloplast-B). Five specimens of each group were thermocycled, and the other 5 specimens were stored in distilled water. Subsequently, the adhesive strength of the specimens was assessed by tensile testing. The resulting data were analyzed by using a 3-way analysis of variance (ANOVA) (α=.05)., Results: After thermocycling, the adhesive strengths of all the resilient liners were found to be statistically different from each other for the same denture base polymer (P≤.012). Mucopren Soft displayed a high mean ±standard deviation adhesive strength to Lucitone 199 (1.78 ±0.32 MPa), followed by Molloplast-B (1.27 ±0.21 MPa) and Permasoft (0.66 ±0.06 MPa). For Ivo Base CAD, Molloplast-B exhibited a high mean ±standard deviation adhesive strength (1.70 ±0.36 MPa), followed by Mucopren Soft (1.11 ±0.16 MPa) and Permasoft (0.53 ±0.04 MPa). Molloplast-B displayed high mean ±standard deviation adhesive strength to Denture Base LP (1.37 ±0.08 MPa), followed by Mucopren Soft (0.68 ±0.20 MPa) and Permasoft (0.32 ±0.04 MPa). The adhesive strength of the majority of resilient liners not exposed to thermocycling was statistically different from each other for the same type of denture base polymer (P<.001). The only exception was the difference between the adhesive strength of Molloplast-B and Mucopren Soft to Lucitone 199 with mean ±standard deviation values of 1.42 ±0.18 and 1.66 ±0.40 MPa, respectively, (P=.067). Without thermocycling, the mean ±standard deviation adhesive strength to Lucitone 199 of Permasoft (0.57 ±0.02 MPa) was statistically different from that of Molloplast-B and Mucopren Soft (P<.001). Molloplast-B displayed a high mean ±standard deviation adhesive strength to Ivo Base CAD (1.83 ±0.25 MPa), followed by Mucopren Soft (1.26 ±0.19 MPa) and Permasoft (0.58 ±0.08 MPa). Molloplast-B displayed a high mean ±standard deviation adhesion to Denture Base LP (1.76 ±0.23 MPa), followed by Mucopren Soft (0.88 ±0.14 MPa) and Permasoft (0.25 ±0.06 MPa). Only Molloplast-B was significantly adversely affected by thermocycling (P=.009)., Conclusions: Molloplast-B displayed high adhesive strength to both CAD-CAM denture base polymers regardless of the storage conditions. Mucopren Soft displayed high adhesion to Lucitone 199. Permasoft presented moderate adhesion to PMMA-based denture bases and low adhesion to DBLP. Combining Permasoft with Denture Base LP should be considered carefully and limited to short-term use. Thermocycling had a detrimental effect on the adhesive strength of Molloplast-B., (Copyright © 2022 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Silicone elastomers are usually produced via addition or condensation curing by means of platinum‐ or tin‐based catalysis. The employed catalysts remain in the final rubber and cannot be recovered, thus creating various economic and environmental challenges. Herein, a light‐mediated curing method using multifunctional silacyclopropenes as crosslinker structures was introduced to create an effective alternative to the conventional industrial crosslinking. To evaluate the potential of the photoreaction a model study with small monofunctional silirenes was conducted. These investigations confirmed the required coupling reactivity upon irradiation and revealed an undesired rearrangement formation. Further optimization showed the reaction selectivity to be strongly influenced by the substitution of the three‐membered ring system and the reaction temperature. The synthesis of multifunctional silirenes was described based on the most suitable model compound to create active crosslinker scaffolds for their application in silicone curing. This photo‐controlled process produces catalyst and additive free elastomers from liquid silicones, including hydride‐, hydroxy‐, or vinyl terminated polydimethylsiloxanes. [ABSTRACT FROM AUTHOR]

Transformation of H2PtCl6 over time under the action of 2-octanol has been studied by NMR, IR spectroscopy, GLC, and GC/MS. It has been found for the first time that the alcohol in a H2PtCl6 ⋅ 6H2O–2-octanol solution is hydrochlorinated to give 2-chlorooctane. Dehydrated platinum chlorides catalyze the elimination of methyl groups in trimethylchlorosilane and hexamethyldisiloxane, which leads to the formation of polydimethylsiloxanes. It has been assumed that the resulting π-complex of H2PtCl4 with octene-1 is not stable in a hydrochloric medium and rapidly decomposes to release chloroalkyl. [ABSTRACT FROM AUTHOR]

Background Context: Cutibacterium acnes (C. acnes) is a gram-positive facultative anaerobe found in the deep sebaceous follicles of the skin on the shoulder and back. C. acnes has been increasingly recognized as a pathogen in spinal surgical site infection (SSI) especially in the presence of instrumentation.Purpose: This study assesses whether a silver carboxylate-doped titanium dioxide-polydimethylsiloxane (TiO2-PDMS) coating can decrease C. acnes adherence and biofilm formation on PEEK and four other commonly used spinal implant materials, stainless steel, cobalt chromium, titanium, and titanium alloy.Study Design: We compared the adherence of C. acnes over 24 hours between uncoated, 95:5 TiO2 to PDMS ratio with 10× silver carboxylate coating and a 100% silver carboxylate coating on each implant material, which were uniformly saw cut and sterilized. Implants were then subjected to scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM).Methods: Samples were coated using 95:5 TiO2-PDMS 10× silver carboxylate, 100% silver carboxylate, or left uncoated. C. acnes was applied onto the samples and allowed to adhere for periods of 4, 8, 12, 16, or 20 hours. Nonadherent bacteria were then washed from the samples. These samples were then allowed to continue incubating for a total of 24 hours. SEM and confocal laser scanning microscope were used to visualize all samples for the presence of biofilm and quantification of C. acnes adherence at each time point.Results: The 95:5 TiO2-PDMS 10× silver carboxylate coating was able to significantly decrease C. acnes adherence on PEEK after 8, 12, 16, and 20 hours of adherence. No statistical difference was found between the 95:5 TiO2-PDMS 10× silver carboxylate coating and the 100% silver carboxylate positive control. We previously observed extensive C. acnes biofilm formation on uncoated PEEK, but none on PEEK coated with either the 95:5 TiO2-PDMS 10× silver carboxylate or 100% Ag coating . Furthermore, no biofilm formation was observed on stainless steel, cobalt chromium, titanium, and titanium alloy coated with 95:5 TiO2-PDMS 10× silver carboxylate or 100% Ag coating.Conclusion: A 95:5 TiO2-PDMS 10× silver carboxylate coating decreases C. acnes adhesion and prevents biofilm formation on PEEK and other common orthopedic implant materials.Clinical Significance: A 95:5 TiO2-PDMS 10× silver carboxylate coating may help decrease spinal SSI due to C. acnes, especially in procedures with instrumentation. [ABSTRACT FROM AUTHOR]

This paper presents a study concerning the macroscale deformation of soft stamps for nanoimprint lithography. Composite stamps consisting of two or three layers were prepared with varying process parameters, and the bow of the stamps was investigated with an optical profilometer. Deflection measurements were compared with results from a mechanical model in order to prove its validity. The composite stamps were prepared from polydimethylsiloxane (S-PDMS) and OrmoStamp® layers on different substrate materials (silicon or AF-32-glass). The influence of selected preparation parameters on the deformation was investigated, such as layer thickness, curing, and hardbake temperatures, as well as UV-exposure intensities. It is discussed how an appropriate choice of preparation parameters can reduce the deformation, too. By decreasing the curing intensity of a thin OrmoStamp layer, coated on top of a silicon wafer, from 200 mW/cm2 to 2 mW/cm2, the deformation was reduced from 6 µm to 0. It is shown that the mechanical model is capable of predicting the deformation of composite stamps consisting of OrmoStamp layers on top of a silicon substrate. Further on, deformation results for S-PDMS top layers are presented and discussed. As a promising process option for the reduction of stamp deformations, a new, room temperature curable PDMS recipe is introduced. For composite stamps prepared with this material, the deformation value was reduced below 10 µm, compared to values ranging from 10 µm up to 127 µm for thermally cured S-PDMS (50°C or 70°C). Finally, different two-layer stamps were coated with an additional third layer and measured again, in order to investigate the deflection for tri-layered cases. The research is of high relevance for the fabrication and application of substrate conformal imprint lithography stamps with minimized deflection. [ABSTRACT FROM AUTHOR]

We report the cases of 2 women who had urethral bulking injections with polydimethylsiloxane for stress urinary incontinence with intrinsic sphincter deficiency and reported initial improvement of symptoms followed by rapid return of stress urinary incontinence several weeks later associated with extrusion of the bulking material. We hypothesize this unique adverse outcome could represent immune rejection of this urethral bulking agent.

Biocompatible polymers, such as polydimethylsiloxane (PDMS), are the materials of choice for creating organ-on-a-chip microfluidic platforms. Desirable qualities include ease of fabrication, optical clarity, and hydrophobicity, the latter of which facilitates oxygen transport to encased cells. An emerging and important application of organ-on-a-chip technology is drug discovery; however, a potential issue for polymer-based microfluidic devices has been highlighted by recent studies with PDMS, which have demonstrated absorption (and thus loss) of hydrophobic drugs into PDMS under certain experimental conditions. Absorption of drug in the polymer can also lead to undesirable transfer of drug between adjacent microfluidic lines. Given the benefits of polymers, it is essential to develop a comprehensive understanding of drug absorption. In this study, we considered convection, dissolution, and diffusion of a drug within a polymer-based microfluidic device to characterize the dynamics of drug loss in a quantitative manner. We solved Ficks 2nd law of diffusion (unsteady diffusion-convection) by finite element analysis in COMSOL®, and experimentally validated the numerical model for loss of three hydrophobic molecules (rhodamine B, cyanine NHS ester, and paclitaxel) in PDMS. Drug loss, as well as the unintended mixing of drugs by adjacent microfluidic channels, depends strongly on platform design parameters, experimental conditions, and the physico-chemical properties of the drug, and can be captured in a simple quantitate relationship that employs four scalable dimensionless numbers. This simple quantitative framework can be used in the design of a wide range of polymer-based microfluidic devices to minimize the impact of drug absorption.